Upgrading CXL2012 - CXL Platinum on STEAM

[nicko2u]

Hi,
what is going on with Steam?, I'm sure when I first seen CXL Platinum come out owners of CXL 2012 could purchase CXL Platinum for the heavily discounted cost of around $4. It seems now when I try this Steam wants to charge me the full cost $20.

What gives on that?

Also are no update/fix patches coming out for CXL 2012 owners of the game?